a = 10
b = 20
a = b
print(a)
print(b)
print(type(a))
c = 0.2
print(type(c))

#计算四个数字的方差
avg = (67.5 + 89.0 + 12.9 + 32.2) / 4
total = (67.5 - avg) **2 + (89.0 - avg) **2 + (12.9 - avg) **2 + (32.2 - avg) **2
ret = total / 3
print(ret)